Fog dispersal system



7 sheets-sheet 1V lNvENToR K//zerz Kao/'stm ATTORNEY June 6, 1950 L. Kools'rRA FOG DISPERSAL SYSTEM Filed Feb. 15. 1946 June 6, 1950 l.. Kools'rRA 2,510,118

' Foe DISPERSAL SYSTEM Filed Feb. 15, 1946 7 Sheets-Sheet 2 jl 4 v {NvEN-rog l lamerz Koam BY Mw ATToRNEY June 6, 1950 L. KoolsTRA 2,510,118

Foc; DISPERsAL SYSTEM Filed Feb. 15, 194e 7 sheets-sheet s 38 l vial' Il www" I mi MI v| nf ym..

www y ,il Uli f3 45 35 Fif7 INVENTOR ATTORNEY I 7 Sheets--Sheerl 4 Filed Feb. l5, 1946 d 1w mw. n 2 MK@ m a o .L my m c j m Y 6 a /f 70 w Lm. 9 V M June 6, 1950 L. KoorsTRA Foc DIsPERsAL SYSTEM 7 Sheets-Sheet 5 Filed Feb. l5, 1946 Fig. 25

O I f 30 al *0,- 1 a y JL "l, @o Pfff laz'zerzf ffoaisra BY y INVENTOR ATTORNEY June 6, 1950 l.. KooIs-IIA 2,510,118

FOG DISPERSAL SYSTEM Filed Feb. 15, 1946 '7 Sheets-Sheet 6 I f INVENTOR ATTO R N EY June 6, 1950 KoolsTRA 2,510,115

FOG DISPERSAL SYSTEM Filed Feb. 15. 1946 '1 sheets-sheet 7 'j INVENTOR. l amer Koo/.stm

l BY

4/ ATTORNEY H tending Joeyond each side'off-the runwayfbeing Patented June 6, 195

Llei

` The .present invention. relates to hnproyeinents in, iogj dispersal systems. j Systemswofj thisoliar- 1 acteriare espeoiallydesigned ierland particularly .useful in clearing aircraitjanding areas,` suehfas -an airfield runwayorlanding strip, to permitane inshalla n 'the ,uninterrupted aircraft operatingA schedule? irre- IiYed from speotive "of adverse atmospheric 'gnditions While such systems arenprimarily adapted'` for land installations,` theyare A. oapable of use with I minor modications. I in "floating` installatiorisplO'i s ucf:h asv aircraftmarriers 01:3 seadromes. Fo'g is, for m'ed 'oicondensedaqueous yapoi; suspend'edjin the atmosphere ator near the suriaoe ,'oir the earth and is freqnentlyof,su'iiicientde sity Qate'the'lansng area, or. when the area is logatecl; to judgewland-SZOl vSie ing conditions with suicient aouraeyto' insure ,safelandnes Undersuh 'i schedules are Y interrupted, yo onsidrevrable tj(financial lossis smfered due to iairraft beine g'rvlrlded during the fog-period and passenger reservations-:25 i n Y anelled, and. asubstsntarlpiss in ,pa hat- Afgo'odwyill.resultsglllof; is'thusjoonsidered nepi --ing---and vaporiz1ng requi edFl/fe wier;` i tial Vthegreatsilolostales to the/Mdesiredfgoalnigall- 53o rglloustion is aompanied llay aV cbnsiderlle weather civiluair transportatio ilarprobarnount'lof ""if'iseries to A -lapiabie lems existginjthe operat onoinrn y ports-- 30-L deereast0 an @Ven gfeatelideelteeslu@ witheigenissbf aerialwarfaremvThe fog dispersal problem'for `aircraft landing fields is complicated'bythelargeareas*involved l. in such installations, runways of300025000`feet -35 inv length loeing customaryl and a clear areaexphase system has artim onfiilitry desirable for substantially its entire length l 'Aide "iewhilecostszotinstallation,andoperation are. not p rniall determinative in so far as milita11y.a-irports are-= 40 w concerned-such .oosts` are ,major factors- Vim the tlieproiisionl of 'a fog-dis installation offanyoeidispersal;Sistemi .t faz-,civil evapotn Wp@ Whih airport. Economical Qperati0r1ans1ss ec. 11s' in fuflderifib vidie the oaseoi militaryiairportafrapidity ot s agting fera-t ng'per-un-i mfupand completely. shutting down,are usT F'ssen-174:51- spe'cifie ob'Jectis tial to the wide use of anyiogQdispersasistem. f-sysrterniohf thee Whileyariousmethods ovf f og, dispersal .have rangefofslicfuA v,been heretofore proposed, the only k varyinfr'om atilellw'flaslpoint 'gasohas heretofore proved suiiiientlyeiective and 'gliiiesf tello olati1higle1-iiash---wintiiielsoils reliable to have gone into actual use ini/folveiv the, .501;- suchaskereseneslonilliesel;iuelsi Ainrtherspedispersal or-dissipationof-fog by-sthe'release of Jk:i1-ieolojeot'sv the provis'ioof `ajfuello'urningffog enormous quantities of heat; direCtlyJintdthe-at- Ydispersa-l'szs'sten'i having a-substan-tiallfinstan- 4-mospl1ere alongr oppositesidesfof thejfrunway the taneousv stari tiz'1g`up`v period to reaoh'nrmal heat transmitted by radiation-r and oonveqtion i thermal ,oal'aNa-oitvv operationfover itsentire lgth s 1Jeinersufficientto evaporate theiinely-'dividedf-v r-wwithoutful# preheatingand-an Air'istaritaneus y flame results.

- with.

cutting-off of the fuel burning period with elimination of residual burning. A further specic object is the provision of a fuel burning fog dispersal system having a relatively low cost of manufacture, installation and operation, requiring a minimum alteration of existing airports, and affording little, if any obstruction of the airport to aircraft operation both during and after installation. A further specific object is the provision of a fuel burning fog dispersal system in which the fuel burning apparatus is divided into sections longitudinally of the runway with a selective control of the operation of each section.

In accordance with my invention, a fuel burning fog dispersal system is provided in which a liquid fuel is discharged into the atmosphere in a highly atomized condition in a multiplicity of jets arranged in groups with the atomized jets spaced suiciently to avoid such interference between adjacent ames Ywhich would cause smoky combustion conditions, and yet close enough to permit interignition of the fuel jets of each group, so that a substantially continuous line of clear While in its broader aspects, my invention includes both fluid and mechanical atomization of a-relatively wide range of liquid fuels, it is more specifically directed to a system for the high pressure mechanical atomization of low grade fuels, such as the kerosenes and Diesel fuel oils, because of the substantially lower fuel cost and power requirements and-other advantages of such a system.

Heretofore in liquid fuel burning systems employing mechanical-pressure atomization, both latomization and subsequent combustion have been effected in a closed chamber such as a furnace, with the benefit of hot surrounding refractory-faced walls, and usually with the benefit of preheated fuel. In such systems also, certain auxiliary apparatus is required to maintain a supply of air to the discharging atomized fuel, and to direct such air into intimate contact there- In prior systems, therefore, where furnace environments are involved, a suitable degree of fuel atomization has been effected with relatively low oil supply pressures, the usual practical maximum range being from about 'l5-p. s. i. Y to 300 p. s. i. l

`higher degree of fuel atomization must be effected than heretofore required as for example in mechanical atomizing furnace burners. At pressures such as 300 p. s. i., the resultant conical spray is too coarse for satisfactory use in an unheated open atmosphere because the droplets in the spray cone would not provide sufficient surface contact with air to enable each fuel droplet or particle to be consumed-completely before it reached the end of its trajectory.

An important feature of my invention therefore is to speed up the combustion reactions by atomizing the fuel at pressures substantially higher than formerly employed, preferably at pressures of the order of 1G00 p. s. i. and above, firstly, to effect ner atomization of fuel particles to facilitate ignition and flame propagation,

y and thus provide more rapid combustion, and

secondly, to provide a higher velocity of each thus improve the admixture of oxygen to support combustion. When such higher fuel pressures are employed, the increased pressure -drop through the atomizer orifice results ln a spray cone of high velocity oil particles which acts to induce a flow of adjacent atmospheric air in a corresponding direction toward the combustion zone. By arranging the atomizer outlet at a predetermined position relative to ground level, and for discharge in an upward direction therefrom, the ow of air induced by the high velocity conical spray enhances air ow into proximity with the atomized fuel so that attainment of smokeless combustion is facilitated without the use of auxiliary air-supplying and air-directing apparatus.

At the higher atomizing pressures which I propose to employ, the resulting neness of fuel atomization also makes it possible t0 operate with unheated fuel regardless of outdoor temperatures, thus effecting a further economy. Operation at the higher fuel supply pressures also results in higher rates of fuel now per nozzle which with the fine atomization attained elects a higher heat release per nozzle or burner, thereby reducing the total number of burners required and, furthermore, providing a concentration of heat conducive to the maintenance of a high temperature zone into which the atomized fuel is continuously discharged, an advantageous environment for smokeless combustion of lower grade fuel oils.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specic objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of my invention.

Of the drawings:

Fig. 1 is a diagrammatic layout, in plan, of a fog dispersal system constituting an embodiment of my invention;

Fig. 2 is a diagrammatic layout, in elevation, of the system illustrated in Fig. 1;

Fig. 3 is an enlarged partial plan view showing details of Fig. 1;

Figs. 4 and 5 are vertical sections taken along line 4--4 and line 5 5 respectively of Fig. 3;

Fig. 6 is a partial side view, and Fig. 7, a corresponding enlargement partly in section, o the multi-tip burner included in Fig. 5; i

Fig. 8 is a plan view of Fig. 7;

Fig. 9 is a sectional view of Fig. 7 taken along 0 fuel particle relative to the adjoining air and7 Fig. 10 is an enlarged underside View of the sprayer plate included in Fig. 7;

Fig. 11 is a sectional view taken along line I II of Fig. 10;

Fig. 12 is an underside View of a modified form of sprayer plate;

Fig. 13 is a side view, partly in section, showing an ignitor unit in relation to a burner;

Fig. 14 is a plan View of Fig. 13;

Fig. l5 shows an element of the ignitor unit;

Figs. 16 and 17 are enlargements showing details included in Fig. 13;

Figs. 18 and 19 are side and plan views respectively, similar to Figs. 13 and 14, including a modied form of burner;

Fig. 20 is a side View, similar to Fig. 13, showing a burner guard;

Fig. 21 is an end view of Fig. 20, partly in section along line 2|--2l;

Figs. 22 and-23 are enlarged side and plan views i respectively o fa burnerarranseineht included in; Figs. 1 and 2; l

Fie 24. is a daargininettt plan View. Similar t0 Fig.; 23,. showing 2 modified. burner arrangement;

Fiss ,25f and 26' are Side and vplan Views ,respectively, showing an arrangement ofv multi-tip burners ofmodted construction;

Fie- 27 is. a plan layout of the. main. fuel Sterage, and feed pump unit;

Fig. 28 is a side view of the drain pump unit;

l Fig. 2Q is a partial plan view of the pump unit illustrated in Fig, 2 8;

Fig. 30 is an enlargement, in section, of a drain- -purnp unit detail;

Figs. 31 and 32 are diagra mm atic layouts, in.; elevation-and-in plan respectively, showingamo d irisation of the system disclosed in Figs. 1 and 2;y

Fig. 33 is a side-view, similar to Fig. 13, includingfmodieations of burner nozzles for the lsystem ofv Figs. 31 and 32;

Figs. 34 and 3,5 are sectional views of Fig. 33 taken along lines Sli- 34y and 35-35 respectively;

Fig. 36Y is a side View, similar to Fig. 18, includingfa further modification ofy burner nozzle; and

Fig. 37 is a s ectional view of Fig. 36 taken along line 37-31.

Figs. 1 and 2 illustratey an embodiment of my invention in the form of a fuel burning fog dispersal system installed in relation to an airfield. runway 2, it being understood that the illustrationsare diagrammatic to indicate the general arrangement of parts without regard to specific dimensional relationships. Burners are arranged in spaced relation inrows 3, Il, at oppositev sides of the runway and in each row the burners are divided into main groups or sections A, B, C, D and E, having separately controllable fuel supply lines 5, 6, l, 8, 9, to permit selective operation.

tion andtfuelwithdrawn from allf or selectedV 'pori-'1 tienathedrain line being suitably installed below therrlevel off the various fuel supply linesv at an inclination; tothe horizontaland having its lowermost end connected toa drain pumpunit. I5,.

and the connection 2| having a plug valve- 23.'-y

therein operable in unison with` the plug valve I9 as detailed in Figs. 3 and 4. The valve control: mechanism comprises` an operating lever 20 mounted 0n thel stem of each fuel valve I9-and provided with handles 22 at opposite ends, afsimilar lever 29a; being mounted on the stem of each corresponding drain valve 23v and pivotally con,- nected to the operating` lever 20 of valve I9 by link` bars 33. The control valves for the respective sections are grouped within valve pits 24,

" 26, 21', 28 as indicated by rectangles in Fig. 1

Where advection fogs normally approach in one direction, the burners may be installed. on the Windward side of the runway only. The groups A, B-V and C are further dividedto provide secondary separately controllable groups or sections of;- which the burners. Illalternate asY shownin eaclrk of the rows 3randd. By way of example, theburner sections. A, B, C, D', E, maybeconsdiredfas having a combinedlength of 3000 feet or morealong arunway. 2 ofj 150.feet in width, each., row of burner sections being` spaced from the; runway by a. distancev of= approximately` 100 orf20Qfeet asa, minimum.

Fuel is supplied under pressure to the systemby/gmeans of pumping apparatus'l II arrangedfor example as in Fig. 27, the. discharged fuel beingy deliveredthrough feed main I2and its branches I2u, |212, I 2 0, to` the` section supply lines 5, 6, 1, 8, 9,; to which the burners ofv respective` sectionsl are connected.V

In the installation shown, where the' terrain slopes; graduallyV from oneend of theV runway toward the other, each burner line is installed horizontally below groundlever, and successive lines at progressively differentelevations correspondingto the slope `of the terrain. Thefeedmain I2; inclusive. ofits. branches, isalso laid horizontally, preferably` atA or belowV the level of theflowest sectionline 9. Individual burners are connected tothe section lines. through risers I3 and 13g. of suitable lengths .to elevate each burner outletto a; position superjacent groundlevelv atfwhich anadequate flow, of;` atmospheric air may be maintained to the zone of fatomized fuel.r discharge.

A.- ,drain lineY I llz-is-v provided through which Vthe fuel,v distributingsystem maybe-.placed undersucf- 755-. system, aihigh degree l of fuel Aatomizationfy is'I L provide a high degree ofatomization and a'hlighf. rate, of-heat liberation usingvarious low gradel hydrocarbon oils. Burners lo for sections A, B andC include a flat sided body portion 3l in which each nozzle 32 'is secured as by a threaded connection 3ft, a group of three nozzles being employed having axial discharge orifices fin a commonr plane, each outer nozzle diverging from the central-gnozzle at approximately As assembled ineach row 3 or 4, all nozzles for agiven section A, B or C dischargeyupwardly in al common vertical plane, as seen in Figs. 3 and 5. Burners 3l)l for groups D and E utilize the same form of n'ozzleeV 32 but in different relation as shown in Figs. 22 and/23 yto be later described.

The burner body portion or block 3| may be formed from plate stock suitably machined to provide intersecting bores 36, 31, 3l, for` conducting fuel from therliser I3 to each of the noz@ f zles 32, each nozzle body SS-being suitably formed from nat-sided bar stockand having circumferentially spaced ports 39 extending from a central passage vil to an annular fuel distributing recess 42 at itsouter end. A sprayer plate-43, havingv a whirl chamber 45 therein terminating in the orice 35,' is formed with four transverse slots i6- for conducting fuel from the recess 62 intothe whirl chamber i5 in substantially tangentially directed streams; the slots 46 entering a cylindrically walled portion 47 of the chamber rearwardly of the conically walled portion d8; The sprayer plate:

sential to enable the fuel to be burned in the open with a clear flame, and preferably without preheating of the fuel. Thus, for a single nozzle 32, when the fuel isa low volatile high flash point oil such as No. 3, Diesel oil, atomizing pressures ranging from 1000 to 1500 p. s. i. are desirable for capacities ranging from about 180 to 1100 lbs. of oil per hr. using a graduated set of sprayer plates 43; the capacities varying from about 180 to 230 lbs. of oil per hr. using a sprayer plate 43 having an orifice area of 0.001018 sq. in., and capacities from about 880 to 1100 lbs. of oil per hr. using a sprayer plate having an orice area of 0.003167 sq. in.; in each instance, the ratio of total tangential port area to orifice area being desirably maintained within limits of about 3:1 and 4: 1.

Y In general, for a given plate and capacity, higher atomizing pressures are required for fuels of heavier grades, and lower atomizing pressures for fuels of lighter grades, the latter including for example such lighter petroleum products as kerosene and gasoline which may be satisfactorily atomized at pressures between 500 and 1000 p. s. i. For a given fuel, within the permissible range of atomizing pressures, fit will be found that a higher pressure always produces the better result, and under wind conditions is often required in order to provide adequate stability of flame.

A burner l having three nozzles 32, using the largest size sprayer plate of the above mentioned set, may therefore be utilized to provide an output of 3300 lbs. of oil per hr. when supplied with No. 3 oil at 1500 p. s. i., a row of such burners operating at spacings of 15 feet from a single burner line 5, for example, providing an equivalent thermal output capacity of about 12,500,- 000 B. t. u. per yard per hour, a thermal output commonly expressed in therms as 125 therms per yard per hour. For a complete section A with the burners of both lines 5 in action, the thermal output would of course be doubled.

For practical purposes however, from a standpoint of economy, and to provide a lower flame limited to about 7 or 8 feet in height, a thermal output of about 60 therms per yard per hour per burner line 5 may be considered a suitable maximum making a total output of about 120 therms per yard per hour for a complete burner section A, B, or C at one side of the runway, or for two half-sections A, B, or Cr operating simultaneously at both sides of the runway; the maximum available output being about 240 therms per yard per hour if complete sections A, B, or C should be operated simultaneously at both sides. Such outputs may be provided, for example, by burners I0 of each line 5, 6, or l arranged on centers of l5 feet, and utilizing No. 3 oil supplied at a pressure of 1500 p. s. i., the sprayer plates in this instance each having an orifice area of 0.002124 sq. in., and a capacity range varying from about 300 to 520 lbs. of oil per hour at pressures ranging from 500 to 1500 p. s. i.

In the end sections D and E a somewhat lower maximum available output may be provided than in sections A, B or C at the approach end of the runway; in sections D and E the burners 30 being arranged in pairs, and each burner including only a single nozzle 32 discharging through an orice area of 0.001018 sq. lin. Adjacent pairs of burners 30 are suitably spaced on centers of 4 feet and when supplied with No. 3 oil at 1500 p. s. i. provide a thermal output per section of about 65 therms per yard per hour, the combined output of two sections D or E at opposite sides yard per hour.

In the operation of each burner l0 or 30 at the pressures and capacities indicated, the fuel from each nozzle 32 s discharged into the atmosphere in an upward direction in the form of a high velocity conical spray which facts to induce a flow of' adjacent atmospheric air to the combustion zone. While the exact course of the air flow in the zone about the atomizers has not been determined, it is believed that air which is involved in the fuel combustion process approaches horizontally along the ground surface from all directions, and that its direction of flow is altered in the zone immediately Surrounding the atomizers so that it flows upwardly in contiguous surrounding relationship to the conical pattern defined by the trajectories of the high velocity fuel particles discharged from the atomlizer. The contiguous relationship of air ow with respect to the fuel particles, particularly as the latter become more widely separated at increasing distances from the orice, permits the embracing flow of air to diffuse inwardly and to be entrained in the inter-particle spaces by reason of the higher velocity fuel particles for prompt and complete combustion of the atomized fuel. Since oil ow velocities are maximum adjacent each nozzle ori-ce 35, it is desirable to position the orifice at a location above ground level where such velocities can enhance the natural movement of air toward the combustion zone. At the same time, it is desirable to install the nozzle as close to ground level as possible so as to limit the height to which the flame extends, and also to lessen interference with ground traffic. In view of these various considerations, each burner l0 or 30 is set so as to elevate each nozzle orifice to a position of about three inches Iabove ground, for example. In a burner having a plurality of nozzles as in the case of a burner l0, the indicated suitable height is that of the lowermost positioned orifices.

In each row 3 or 4, at least one burner of a selected group or plurality has associated therewith an'oil ignitor 52, as indicated in Fig. 3 for example, for initiating combustion throughout any section or row, each burner thus lighted serving as a pilot for lighting off one or more adjacent burners so that there results a progressive ignition of all successive burners to which fuel is being supplied.

The ignitor assembly for a burner l0, as de- Y tailed in Figs. 13-17 includes a bracket 53 secured to the burner riser IS for maintaining the ignitor element 52 in predetermined relation to a burner nozzle 32. It has been found that with the type of nozzle disclosed, when a burner is started up, as by opening a fuel valve I9, there 1s an interval during which fuel pressure at the nozzle must build up to normal, with the result that the initial discharge is a conical spray of larger included angle than when the internal fuel pressure has reached its high normal value and the burner is operating at full capacity. Advantage is taken of, this characteristic of operation by positioning the ignitor element l52 so that its effective heating portion is contacted by oil from the initial wide angle low capacity spray 54 upon starting up, but is out of the path of the narrow angle high capacity spray 56 during normal operation.

The ignitor element 52 is formed from a calrod electric heating element, a product of General Electric Company, Schenectady, N. Y., the

basic-construction vof w-liich includes 1an internal helical coil resistor y.centered ywithin "a seamless metal .tube or sheath 4yszhinh is 'packed with :magnesiumeoxide powder `serving .as :electrical insulation fand a .heat 'conductor between theresistor and sheath. The resistor is confined to .the required effective heating length of the unit while leads therefrom extend to terminal portions at opposite ends.

For purposes of my present invention, the effective heating length of the ignitor element 52 is wound into a helical 'coil 51 of relatively small diameter having substantially contacting turns as vseenin Figs. 13-1'5. The internal coil resistor 58 has one lead 59 grounded tothe sheath at end 60 which is plugged into a hole 6| in the bracket 53, the :other lead '62 extending to a metal connector 63 providing the vvterminal plug 64, an insulating washer y65 being interposed between the metal sheath of rod'52 and the metal connector 63, of .greater diameter than both. The coil 51 comprises at least .two-and-one-half full turns so as to block radiation of. Vheat from one or more inside .turns .on three sides, .for example, in the formsshown, sideward radiation from the central coil orturn 61 is `blocked by the two outer coils 68 while inward 'radiation is blocked by the opposite inner wall of the .:coil. As a result, the

sheath of the central coil -61 may beoperated at a temperature of 1500"F. with a minimum wattage input tothe resistor coil 58 which is thereby maintained at a minimum Vsafe operating temperature, the temperature 'of 'the central coil sheath being labout`250" F. hotter than if a single, fully exposed turn -or -length were used, at an increased wattage inputv f only about ten percent. Theelement 52 may be operated from the usual 110 volt supply so that no special equipment such as transformers is necessary.

During operation of burner vIll the flame starts about 6 inches from the tip of'nozzle 32 and thus the exposed portion of ignitor 52 is located in a relatively cool Zone, under the vcold liquid spray cone, where it is shielded from intense flame radiation; in this position also, the ignitor being disposed in a current of air induced by the high velocity oil discharge, vwhich helps to keep the element from becoming overheated should the power be left on during vburner operation. The ignitor can also serve as a vthawing element as it is close enough to the burner for effective heat transfer, it being capable of raising the temperature yof the 4burner about 70 F. above the ambient temperature.

The lower terminal end 64 -of the ele/ment 52 extends downward below ground level within a protecting tube or casing 69 joined at its lower end to aterminal housing 'or cap 1| within which a slideable connection is made to the voltagesupply in a zone of relatively low temperature, the casing 69 extending through a 'hole 12 inthe bracket 53 and the bracket being` slotted transversely of the hole as at 13 to form a clamp in which the casing 69 is supported by means of bolt 14.

A weather-tight 'and temperature-proof joint and seal, as detailed in Fig. 16, is provided where the element '52 A.enters Vthe upper end of casing S9, the `formation ofthis joint comprising a stainless'steel sleeve A15 vsecured as by brazing lto the metal sheath Aof ignitor element 52, a loose packing sleeve or bushing 16 `having a close sliding t over 4sleeve '15, and a pac-king nut yor cap V18 19fwithlthe'upper-endof casing 69. The ends ot bushing 16 are beveled asshown, one end engaging a correspondingly beveled end surface Blof the casing and the other end -being engaged 4by a correspondingly beveled inner surface of `the cap. The sleeve 15 .provides a local enlargement of the element 52 yso .as to require .a bushing L16 of 'large Venough ,inside diameter to `enable the washer .65 to pass therethrough when inserting or 'removing the element 52.

The lowerend lof casing v69 is secured Aas by brazing Within' a `counterbore 83 in Va anged stainless :steel 'bushing 84 screwed into nut 85 forming the iopen'd Vclos'ure'oi the terminal .housing 1|. vAninsulating'bushing 86, of :molded mycalex Lmaterial, a rcommercial product including mica as an ingredient, is secured within the :lower end of bushing 84,."and1is'f1tted with an elongated internal lterminal sleeve member '81 `forming ka jackto receive and :provide rsli'deable contact with plug-terminal l64 of element v52,'th'e circuit being completed through #an :adj oiningfconnector `89 and other .suitable electrical conductors Aincluding .a fuse 91 and terminal lead'92 extending outwardly through a tubular extension 93 of terminal housing '1 l, the lead being sealed `to the extension by suitable packing 94 4clamped r'around lead 92 and against vthe tend 'of the extension by a screwed packing nut 95. A'Cap 96 is lsecured to the bottomfend-'of housing 1| to for-m a kclosure therefor.

Figs. 18 and 19 show'the vmanner in :which ignitor 52 may be 'held `in proper V'relation toa burner 30 -of the type used -in sections D and E. In this .instance the 'burner riser |f3a `has an 'inclined upper portion |3b making it desirable to provide a bracket 53a having offset upper 'and lower end portions `91rand'98 respectively, which 'enable the upper portion '91 to be positioned adjacent ground level fas ein the lcase of Ybracket 5-3fwhile enabling the lower endvporti'on'l'98 .to be 'secured 'to the ver-'- ticallower 'portionoriser 13a. The remainder of the ignitor assembly is the same as previously described. In fthis -form of lburner,-a coupling |f9| is screwed to the upper vend -of the Vriser portion |317, and asingle nozzle .32, yof 'the construction already described, fscrewed `into the coupling. A templateor gage |92 may be used in adjusting the ignitor-00H51totheproper height relative to the nozzle, the 'gage having righteang'led surfaces |03, |04, adapted to .be placed in contactwith the flat end `and -at side `surfaces respectively lof nozzle cap 49, `whereby proper adjustment Vof the ignitor is indicated when lignitor 'coil 5-1 is brought into contact lwith the gage surface |65. 'The same pattern of gage |62 may be -used int-he adjustment -of ignitor position for other burners, including va burner |11, for-example, as in Fig. 13.

Figs. 20 and 2l illustrate a-'mea'ns for protecting a burner, or burner and ignitor, from damage by taxiing planes, trucks or 'other' ground trafc. In the form shown, the bracket for supporting ignitor 52 is extended :at opposite-sides of burner riser |3 to lform a Ybase -pl-ate |06 serving yalso as a support for guard v'bars |01 arranged adjacent burner lil'fat opposite sides; The bars |01, suitably -of circular cross-section, are yarched to a height above both the burner nozzle and ignitor so as to provide adequate .protection thereto; the bars being spaced from the centerlines of nozzles 32 to provide clearance for the discharging spray, at the same time affording negligible obstruction to air 'o'w to the .combustion zone; plate |06 being fixed in relation to the burner as by welding |08; and bars .H11 being welded 'at their ends l|09 to plate |116. As'will be understood, a guard of vthis type is similarly adapted for use in other burnerignitor combinations, including that shown in Figs. 18, 19, or with individual burners I or 38 for example, when not equipped with igm'tors.

Figs. 22 and 23 show burners 30 as arranged in pairs in burner sections D and E to provide crossed sprays in parallel pairs, the burner risers I3a be'- ing connected to burner line 8 for example in a single longitudinal row, at alternate short and long spacings suitably of twenty and twenty-eight inches respectively; The burners of each pair discharge in opposite directions in parallel vertical planes oblique to the burner line 8, with alternate burners throughout the row discharging in the same direction toward the same side of the burner line axis, as indicated by arrows, the angularity of discharge with respect to the burner line axis being about as measured horizontally, and about 45 as measured vertically; such angularities and spacing's being generally desirable for average conditions although other angularities may be utilized, if necessary, to obtain different combustion characteristics and flame patterns. Y v

Fig. 24 shows a modified burner arrangement in which pairs of burners 30 provide crossed sprays in opposed pairs, the burners being connected to burner line 8 in a single longitudinal row as in Fig. 23, and the burners of each pair discharging in opposite directions in parallel vertical planes oblique to burner line 8. In this arrangement, as indicated by arrows, alternate burners throughout the row discharge in the same general direction but toward opposite sides of the .burner line axis.

Figs. 25 and 26 show multi-tip burners H2 of modified construction arranged in a row above burner line 8 to which they are connected, each burner comprising a body portion |I3 suitably constructed to distribute fuel from a riser I 3 to three burner nozzles 32a, 32h, 32h, each of the construction of a nozzle 32, arranged at substantially equal circumferential spacings, each nozzle discharging upwardly at an inclination of about 45 to the horizontal, corresponding to the inclination of discharge for each of the two side nozzles 32 in Fig. 11. Nozzles 32a of successive burners H2 are positioned to discharge in one direction in the vertical plane of the burner line axis, while nozzles 32h are positioned to discharge in a generally opposite direction at equal angles to such a plane, each nozzle 32a thus discharging between oppositely directed diverging discharges of nozzles 32h of the next adjacent burner.

The fuel oil pumping equipment for a system as thus far described, comprises a main feed pump unit |I suitably of the arrangement illustrated in Fig. 27 wherein fuel from a main fuel storage or tank farm H5 is pumped in two stages for delivery to the feed main 2 at pressures ranging upwardly to at least 1500 p. s. i. Fuel enters the primary pumping stage I6 through a pipe line |I1 extended as at H8 if 6 l2 |25 comprising a pump |26 driven as by electric motor |21 and discharging direct to feed main I2, the low pressure connection |23 being extended as at |28, for example, to receive fuel discharged from additional primary stage components, if any.

A return connection I 29 is made from main I2 and the outlet of high pressure pump |25 to the tank farm H5 whereby, when all burners are cut off and no fuel is being discharged from the System, the pumps 9 and |26 in both stages may be idled at low' capacity to maintain a high pressure oil supply Yinstantly available the moment the main fuel valve i8 and any burner line valve I9 are opened, at the same time preventing damage to pumps i9 and |26 by maintaining a flow of oil therethrough. The connection |29 includes two intermediate portions |3| and |32 in parallel, the portion 3| having valve |33 therein, being used for recirculating oil as above described, and the portion |32, having valve |34 therein, being used for returning oil drained from the system as will be later described.

The drain pump unit |5 as shown in Figs. 28-29- age tank |38, the pump having an outlet connection |39 extending upwardly to a T I4| from one branch of which a connection |42, through valve |43 and jet eductor |45, is made to the upper part of tank |38, and from the other branch of which a connection |46, through valve |41 and T |48, is made to drain line I4 at its lowest level. A connection |49 having valve |58 therein is made from the remaining branch of T |48 to the suction inlet of eductor |45. Other connections to tank |38 include a valved drain connection |5| at the bottom and a valved vent connection |52 at the top.

The eductor |45 is a known piece of equipment adapted to receive and discharge one body of liquid, or other fluid, through the jet action of a second body of liquid directed therethrough under pressure. As detailed in Fig. 30, the eductor |45 includes a pressure liquid inlet |53 having an inlet connection |42a from valve |43, and an opposite liquid discharge outlet |54 having an outlet connection |42b to tank |38, the suction inlet |53l having an inlet connection |4966. from valve |58 through which liquid is admitted. from drain line |4. Alternate inlet and outletopenings are closed by plugs |51, |58, respective-f ly, as not being utilized in the present arrange--v ment. Liquid entering the eductor through inlet connection |4211 is admitted under pressure to inlet chamber |59 from which it is directed through pressure nozzle |=6| to produce a high velocity jet in alignment with a tapered discharge nozzle or throat |62, the pressure nozzle I6| having its outlet within an intermediate eductor chamber |63 axially spaced from the inlet of the discharge throat I 62. As a result, liquid is caused to now into intermediate chamber |63 through the suction inlet connection |49a and to combine with the jet-producing liquid or operating medium for discharge therewith into and through outlet chamber |64 and connection |421);

When the system is to be placed in normal operation it is assumed that the main fuel valve I8 and all section line Valves I9 are closed to prevent discharge of oil from the system, valve |33 in recirculation line |3I being open and valve |34 in drain return line |32 closed. The main pump unit is then started up to cause o il to be recirculated between unit @H :andthe main [fuel storage lil 5, the foil 'thus being vavailable in feed main |.'2, at its inlet end, at vfthe Ipredetermined inormal operating l:pressure vof 1500 p. s. -for example. The check valve Fili blocks `theiiow of oil from feed fmain l2 'into draini-line i4. The ymain fuel valve l may thenlbe'opened leaving only ysection valves Vili'to be opened when burners are to be .operated When a demand is receivedfor'burner operation, the ignitors S52 `associated with ftheburners arefplaced in lcircuit with 'an electric `current-supply, not show-n, whereupon afteraperiod o'about have reached normal ignition temperature, section Avalves le forthersectionsfto `be operated are opened to :supply oil to fthe burners -at the normal operating pressure. Opening of a feeder valve |9 automatically fcauses 4fthe corresponding drain valve 23 vto `be closed to block oil connection 25| to drain line ie'll. Ignition of the .spray Ifrom successive 4burner nozzles 32 is effected in 'fthe manner already describedwhereupon the electric supply to the ignitors may be cut oil.

Prior itc closing down any burner section, `'the drain pump unit il is operated to -place drain line |4 under suction Iby establishing Aa Vcirculation of oil between pump 135 and tank v'|38 through -eductor IV45, a l-suilicient amount of 'oil lbeing continuously 'retained 'in vfthe :tank 'tolkeel ythe inlet to pump E235 submerged. During this step of the operation, valves f3?, |43 and 350 'are open, and valve |547 closed. vthe Aflow path from the tank to the pump being through line "|36, and ifrom vthe 'pump to the `tank through f' lines |39 and M2, including eductor T45.

When burners are to be closed Jdown, `vfeeder valves vl!! -for the sections to he -renderedinactive are closed, thus cutting off 'the `supply Iof `oil to the sections, and automatically opening the-associated valves "-23 zand 'connections r2| to Idrain line .'|'4. AThe Vsuction continuously lproduced in e'ductor .|45 and vtransmitted Vthrough connection M9 to drain .line le `exerts a piil-l-of .about l p. s. i. vvhiclfi immediately acts to Withdraw oil -from 'all inactive burner 'lines15,6, 7|, '-il'or S, -tl'iereloy relieving residua-1 oil pressure in inac- "tive lines and lrisers and thereafterloweringthe oil level therein so that little'or -no oillis allowed to escape `from the sections vonce the Vvoil supply pressure vthereto has Ibeen cut off. If desired, the withdrawal or oil maybe lcontinued until'all inactive burner 'lines are completely vdra-ined and the 'oil transferred to .the temporary-storage tank |38.

Where there is a slope `to the terrain, las indicated -in vilig. 2, some Vof the burner nozzles "are necessarily at la higher elevation 'than others and, in vsonic instances, the corresponding burner 'lines may allso'be at diierent elevations, `also as indicated; for example, in sections A vand all yburners ill of section A are at elevations 'higher than all burners 3i! of section E, vand'burner line 5, section AA, is also at a higher elevation vthan burner line 9, section E. Assuming thatsections A and E are being shut down, so that" further oil 'supply'to kthese sections is cnt oi, While residual pressure may cause a certain amount of'dribble from most `of the burners, the rmajor escape is due to the dinerence in elevations causing oil to escape from burners at the lower eaevations until 'the level lin both sections A and 'E has been lowered tothe level of the lowermost burnenherein indicated as a burner 35 attlie extreme left of lburner line 9. Thus the withdrawalvo'f oil'from 14 inactive`v sections to at' least illfielevel of the. lower most burner Etherein, obviates the :accumulation -of --relativelylarge quantities fofloil on the ground, land the possibility of vground lires immediately after burner shut-downorrat other times.

yThe -oil lreturned to "tank v|38 may nbewithdrawn through lconnection |5|, forfexamplepfor transportation `back tothe main fuel-storage -or when `the main pump unit is shut downy `may be pumped back to storage by means 'of lpump-unit l5. In `the latter case, -with "the main fuel valve `It closed,valves"|`3'| and|`4f| arezopen, and. valves |113 and |50 closed,to cause Yoilto be lwithdrawn from'tank 5| 38 through lconnection |36 and =to be Idelivered by Apump '|35 rthrough connections '|39 and |46 into dra-inline M through Whichiit continues `past check valve "I'B and globe valve l1 'into'fuel main |2; the -ow continuing through connection |29, including its Ydrain Teturn portion |32, now open, and thus l'toi-the main 'fuel oil storage ||5.

Figs. '31 and 32 varediagrammatic illustrations -of laV modified form of fog dispersalsystern espe- Ycially -arrangedto preventthe escape'of oil from 'any inactivesection or sections withoutthe `necessity of withdrawing oil therefromjthe system being particularly adapted for installation aof burner nozzles at different elevations, las in the ycase vof a slopingfterrain.

Fig. 3l is illustrative of #a Ysingle burner section lF generally similar in `'its relation to a runway. not shown, as any'of 'sectionsn B, 'C,"'1D, Egndicatedin Figs. 1 and 2, yburners -liilbeing larranged at suitable-spacings in a single rowfand connectedby risers I3 to a burner line '|69 having its feeder portion =I'iiSa connected -to ffuel `feed main-12. 4The burner line |69 is installed ysuit- 'ably at substantially the same depth throughout `tofenable risers i3 of substantially'equal lengths `to be utilized so las vto afford uniform `projection -of al1 burners above groundlevel, the burner line |69 sloping in opposite'directions in accordance vwith the slope of lthe terrain, Aand lthereby 5providing an lintermediate lowermost burner line portion to'which 'thefeeder connection m|6911, is-pref erably joined. The feed vmain -"-|-2 `is 'preferably installed horizontally, rat or 'below yfthe 'lowermos't 2b'urrier'line'portionof a singlesection F, as'shown, or where a number of such ysections are involved, Aat or below thelevel ofthe lowerm'ost burner 'line portion of the system, similar to the arrangernentpreviously described.

As in Figs. land 2, feed main 4IZmaybe connected through a main ffuel valve IB to a feed pump 'unit l, the section ordrain 'line "l '4 having one -end portion connected to feed main I2 'through valves i6' and at apoint intermediate Avalve '18 and unit l and its .opposite lowermost end portion lconnected .to suction pump .unit such .as unitfl. vEach section, suchasiF, includes a connection |'1| to suction linev |4 from .the low- .ermostportion of `'its burner vline |69. .Rlug valves |`9 .and .23, .in ,pressure :connection 159e-and suction .connection respectively, .are preferabli7 coupled for operation in unison, as by a-zlink mechanism |12, generally-ofthe typedetailed in Figs. r3 :and 4, a A.strainer H3 lbeing provided in ffeeder :connection 15901. at the outlet side rif-valve |59, :and :the .entire fcontrol 'valve tassernbly "'oeing fenclosed Ewithina vpit 'llt asirepresentedfby f'tlie f'dotted rectangle. A4 vent connection |14 l'including 'a valve :|15 i's'provide'd in leach burner line at the highest Vpoint'therein, or 'at-'each of 'the highest points yasin the case of Vburner-line '169,

the purpose of the vent being toperrnit withdrawal of oil from the line if desired.

'i Each burner E1 suitable for the system of Figs.

31 and 32 preferably embodies a construction whereby the total outlet therefrom is automati- 5 cally sealed against air intake when the oil supply pressure is cut off and the burner line placed under suction. Fig. 33 illustrates one form of burner |81 wherein three atomizing nozzles are arranged in substantially the same relation to l each other and to an ignitor coil 51, as in the case of burner I0 in Fig. 13. Duplicate nozzles |18, |18 are installed in positions remote from the ignitor While the third nozzle |19, providing a different character of spray in starting up, is installed in a l position adjacent the ignitor. In other burners |61 not associated With ignitors, either form of nozzle |13 or |19 may be used throughout.

Each `nozzle |18 includes a body portion |8| suitably secured in burner body 3| as by threads 20 34, a central bore |82 in part 3| terminating in an enlarged outer end cylindrical recess or counterbore |83, the rim or bore |82 at its intersection with the base of recess |83 being beveled as at |84 to provide a circular seat for a stainless steel 25 ball |85. A sprayer plate 43 or 43a, as previously described, is assembled against the outer end of nozzle portion |8| where it is held by cap 49.

When nozzle `|18 is in operation the pressure of oil supplied thereto forcesl ball |85 from its 30 seat |84 into contact with the circular rim -44 of Whirl chamber 45, a position indicated by the dotted circular outline, thus closing off entrance to the whirl chamber except through the innerl ends of sprayer plate slots 46, and thereby causing the oil to enter the whirl chamber in substantially tangentially directed streams as in nozzles 32. In starting up, while ball |85 is being lifted toward its seat against rim 44, the oil enters the whirl chamber longitudinally instead of tangentially and thus for-a brief period is discharged from orifice 35 in a relatively solid stream. The

form of discharge changes quickly however to the normal angularity of spray 'cone as discharged at full capacity from nozzle 92. When the oil supply pressure to burner |81 is cut-off and the burner placed under suction, ball |85 is pulled downward, assisted by gravity, against seat |84 to maintain a seal against intake of air.

Nozzle |19 herein shown adjacent ignitor coil 50 51 includes a nozzle body |86 formed with a central cylindrical closed end fuel pass-age |181 having its inlet end portion |89 of enlarged diameter to receive and hold a bushing Yor sleeve 9|v therein, the bushing providing a beveled circular seat 55 |92 for ball |85 at the inner end of the central bushing passage |93,the seat |92 being spaced a sucient distance from the conical end surface `|94 of passage |81 to permit the required longitudinal movement of ball |95 therebetween.` Cire0 curnferentially spaced fuel conducting ports |95 extend from an inner end portion of passage |81 to an annular groove or recess |96 in the outer end surface of nozzle body |86. A sprayer plate' 43 and cap l49 complete the nozzle assembly as 65 in Fig. 33,

In this form of nozzle, when ball is lifted from its seat |92 by oil supplied tothe nozzle, the oil is released into the inner end of passage |81 from which it is conducted through ports 70 |95 to the annular recess |96 :and thence to sprayer plate s1ots46, the ball |85 being forced against the conical surface |94 where it remains centered with respect to the concentrically arranged ports |95 while oil is flowing. The ball I,75

thus merely acts as a valve and has no effect on the character of spray discharged from orifice 35, the form of spray in starting up and at normal capacity therefore being identical with that discharged from nozzle 32. Nozzle |19 is thus particularly adapted for use adjacent an ignitor 52 where in starting up the initial spray cone of relatively wide angle will contact the ignitor coil 51, whereas at normal capacity the narrower spray;l cone will clear the coil.

When the section F is to be closed down, it is assumed that the suction pump unit I5, or other equivalent means, is in operation to exert a suction on suction line I4. Valve i9 is then moved to its closed position to cut off -oil supply to burner line |69 whereupon valve 23 is automatically opened to place burner line |89 under suction.t The suction pressure assumed to be of the order `of 10 p. s. i. as in the system previously described, is transmitted to 1all nozzles |18 and |19 where it immediately acts to pull the balls |85 inward against their respective seats to seal the nozzles, and thereby the entire section againt intake of air.

The dribble or escape of oil from the nozzles after shut-down is thus prevented, whether due to residual pressure or more particularly to differences in nozzle elevations, a distinct advantage of the system being that no loil need be withdrawn fro-m the system, thereby economizing in the power required for pumping. A further advantage is that the system is maintained in complete readiness for instant starting, with oil at the nozzles, the moment the oil pressure supply is again opened up. Provision is made however for draining the section, if desired, by installing. valved vent connections |14 which When opened allow air to enter the section to permit withdrawal of oil as in the system previously de-y scribed.

Figs. 36 and 3'1 illustrate a burner-ignitor combination, similar to the arrangement in Fig. 18, wherein a modified form of nozzle 91 is indicated, suitable for use in a system such as dis' closed in Figs. 31 and 32, the nozzle |91 producing a character of spray substantially equivalent to the spray produced by nozzle |19 and accordingly being interchangeable therewith particularly in an inclined position adjacent an ignitor. Nozzle |91 may however be installed in any position, with or without association with `an ignitor, and therefore is interchangeable with any other nozble hereinbefore described. Nozzle |91 includes a body portion |98 suitably secured in coupling |0| as by threads 34, and having a central circular fuel passage 20| extending therethrough, the outlet end of passage 20| being enlarged as at 202 to form an intermediate shoulder portion providing the beveled circular seat 293 for ball |85, a second ball 204 being positioned adjacent the sprayer plate 43 where it is maintained in contact with rim l44 at the base of whirl chamber 45 by means of spring 295 urging balls |85 and 204 in opposite directions. Spring 205 is desirably of rectangular formation transversely of its length as shown in Fig. 37 so as to provide corner por-l tions 209 substantially in contact with the circular inner Wall of passage 202 and thereby maintain axial spring alignment `with minimum resistance to axial movement during operation.

It is evident from the foregoing description that the system disclosed affords numerous advantages over prior developments. The general construction is of simple character lending itself to facility and economy of manufacture, installation 25u-roms and"operation.'f` various ruelsmay be used;- anda Widerangeoff* i-,herina1-12capacitiesl attained'. by clangeslnlhe' Sile Off Spaly'r plates' and` in fuel pressures,- used.vv The system affords" instantaneoussmokeless starting using 'a cold fuel;- clean high heat-release combustion while in operation, anda positive cut-oli' of combustion' and fuel Whenbeing' shutdown. The bulk of thev apparatus-along'. the runwayis installed below ground level Where'the'- parts are removed from the zone oiintense heat,- while those parts above' ground level,- being of 'smallsize, present little or no ob- StuCtiOI'l-f to".'el'd`',1".l"1tand furthe-r3 Calif b' e602 nor'ni'cally -made ofstainless metals to resist deterioration both because of their proximity to the llame and Weather conditions Whilein accordance with' the provisions of the statutes I have illustrated and described herein the best-forms of in'yinvention now known to me th'ise'"skillediri the art' W'ill understand that changes may loe-made inthe form and inthe seid of usev of the apparatus disclosed' without' departflgl 'floli'lv the 'Spirit v0f ytlfi invntf- @Over-d -bl? my claims,V and that 'certain features of'rn'y invention may sometimes be'used' to advantage Without a'olfespnding use' 0f other features.'

1. A method-of'fdispersng fog-over an area which comprises discharginga` series of spaced jets of finely aton'iized liduid'fuelinto the atmosphere from points' superjacent ground level with adjacent jets spaced Vsuiiiciently' to avoid flame interference and yet' arranged with' said jets in interignitable'relatiozr, and igni'ting` one of said 'nely atomize'd 'fuel' je'ts` to establish a substanti'ally continuous line of flame;

2L'A'method of dispersing fog over' an .area which comprises' -disc'l'iarging` aseriesr of high pressure mechanically atorr'iifzed`- jets of relatively low volatile high flash/'point liquid fuelintothe 1 vatmosphere with adjacent jets spaced and ar"- ranged so asfto avoid llame interference, and` igniting said atomized fuelfjets in' said'series.v

3. A method ofdisp'ersing fog over an. aircraft landing area which comprises discharging a series tion, and electrically igniting one of said jets to establish substantially continuous'lineA of flame along the side of said landing area;Y 5. lA niethodof dispersing fog overan aircraft landing' areav which comprises 'dischargingv mechanically atomized jets of relatively low'vola'tile high ash point liquid fuel into' the atmosphere at a discharge velocity and frompoints at a level above ground level sufficient to create a substar'rtial induction of the surrounding air into contact with the discharged jets, and igniting said jets t0 establish a high temperature zone of clear llame along one side of said landing area.

6. A method of dispersing fog over an aircraft landing area which comprises supplying a relatively low volatile high flash point liquid fuel ing areaatai- `l'ii'gh4prefssiiie; andatomizingff 'saldi fuel, at said preneurey dischargingtheffuelfin a lseries oi'latorrliz'ed jetsf into-l the atmosphere adj acent groundlev' talong. at least' one 'side of: said land- 'ithfthe jets arranged. inY groups and thefjets1 iri'each groupf in: interignitable relation, gni-tig *one -`oi``v the jets. inf each group and maintainirigl'fa substantially continuous line of f -ame along 'the side .oi said landingarea during the desired aircraft. Aoperating period, controlling the high pressure liquid fuel supply at' `a point'int the fuel suppl-y path` remote` fromithe point. ofato'mized.' fueldischarge; cutting olithe-'higli` pressurelli'quid fuel. supp-ly". at said: remote'point of controlarlo; simultaneously preventingthe discharge' of residualv fuel 'in said-supply pathzbeyond the point of vfuelcutoff 7. A'fog dispersal systemfor an-aircrait landing areascompri'sing a--seriesl of liquid'fuelatomizlingi nozzles spaced'l along.vv one-1 side of said-y landingiarea,f eachM ofx said nozzles* bei-ng'.` exposed tlflroiighoutI to the. atmosphere lsurrounding all of said nozzles-and adjacent fuel atornizing. nozzles' being; spaced'. and"y arranged.: tofdischa-rge iatomiz'ed fuel'-jets` directly Kinto said-atmosphere in interignitablel relation.;- and: means-4l for supplying at atomizable -liduidfffuel'underI pressure to said Efuelatonfiizing; nozzles 8:1- A ffog disperserl system -f or -apredetermined rareafcomprisinga series ot liquid fuel'` atomizing nozzles spacedl relative v to saidarea; said nozzles beingfspacedfandarrangedtdv discharge atomized fuel -1 jets directly intothentmcsphere commonyto allot-:said nozzles in' directions avoid-ing inter- =-"ference vbetvveen adjacent 4flames anda-yet .sufriciently close te be in interignitable -relatiorn rand meansfor supplying van atomizable .Iiq=uid...fuel under pressure to said .nozzles.-

9. A fog dispersal system .for-an .aircraft landving area comprising alpipe line-having groups of liquid-fuelatomizi-ng ,nozzles spaced. along f one side ofsaid-landing. area, adjacent nozzles of each groupf being spaced V.at lesser. distances than the distances .separatingadjacent nozzle groups and being'farrangedto discharge atomized fuel jets directions.. avoiding. interference between adjacent ilamesof each nozzle group and the ilames oi..adjacent nozzlegroups while .havingthe fuel jets. of at least eachnozzle grouptin interignitable. relation. andmeansfor supplying anatomizableliquid fuel under pressure to said pipe .line and4 nozzles.v

10; Afogdispersal system for an aircraft landingarea comprising' a pipe line having groups. of liquid fuel atomizing nozzles spaced. alongA one side-of said landing area, `each of said nozzle groups includingat least one nozzle arranged to discard a jet of atomized fuel in a direction gen.- erall'y. opposite tothe direction oi' jet discharge by at least one nozzle of .the next adjacent group,

adjacent "nozzles of each group; being spaced and arranged to discharge atomized fuelr jets in. di'- recticnsavoidinginterference between the flames of4 eacnnozzle group. and' theaii'ames oiv adjacent vnezzle lgroups when the fuel jets are ignited while 19 and terminating adjacent ground level in burner heads spaced apart in a row s-ubstantially parallel to said strip at one side thereof, said burner heads throughout said row terminating in liquid fuel atomizing nozzles arranged to discharge upwardly in a common substantially vertical plane, each of said nozzles being exposed throughout to the atmosphere surrounding all of said nozzles and thereby discharging directly into said yatmosphere in common with nozzles associated with burner heads throughout said row.

12. In a fuel burning fog dispersal system operative in relation to an airfield landing strip, a pair of underground liquid f-uel conduits installed horizontally along one side of said strip in parallel relation to each other and to said strip, a series of burner heads connected alternately to the respective fuel conduits of said pair and terminating above ground level in noz zles disposed at substantially equal spacings in a row intermediate the vertically projected locations of said underground conduits, each of said burner heads terminating in a plurality of liquid fuel atomizing nozzles discharging upwardly in Adivergent relation in a vertical plane, the axis of discharge of one of said nozzles of each burner `head being substantially vertical.

13. In a fuel burning fog dispersal system operative in relation to a predetermined area, liquid fue] atomizers disposed in a row relative to saidarea, an underground supply conduit in which liquid fuel is maintained under pressure and to which said atomizers are connected, an underground drain conduit having its elevation throughout lower than said supply conduit, and means for simultaneously cutting on the fuel supply to said supply conduit and placing said drain conduit under suction.

14. In a fuel burning fog dispersal system operative in relation to an airfield runway, an underground burner conduit installed longitudinally of said runway, a series of upwardly extending burner risers connected to said burner conduit, a series of burner heads spaced apart in a row paralleling said runway and individually connected to the upper ends of said risers, each of said burner heads including a fuel atomizing nozzle disposed adjacent the ground level, a valved connection between said burner conduit and a source of fuel oil under pressure, and means for preventing the escape of oil from said nozzles during the period of residual pressure decrease therein following the closing of ,said valved connection.

l5. In a fuel burning fog dispersal system oper- Iative in prorirnity to an airfield runway, liquid fuel atomizers arranged adjacent ground level in a row laterally of said runway, a series of underground burner conduits to which said atomizers are connected in groups, a feed main lhaving a separate valved feeder connection to each of said burner conduits, a liquid fuel storage container, a pump connected to said fuel storage container for supplying fuel to said main under pressure, a return flow connection from the i outlet of said pump unit to said fuel storage container', an underground drain conduit installed at an elevation lower than any of said 20 lburner conduits, means including a pump connected to said drain line for withdrawing fuel from any of said burner conduits when the feeder connection thereto is closed, and means including said last named pump for returning the fuel thus withdrawn to said fuel storage container.

16. A method of dispersing fog over a predetermined area which comprises discharging atomized liquid fuel directly into the atmosphere in a series of jets spaced and arranged so as to avoid name interference when said jets are ignited while maintaining a substantially continuous high thermal output zone marginally of said area, and effecting ignition of said atomized fuel jets in said series.

17. A method of dispersing fog over a predetermined area which comprises discharging atomized liquid fuel directly into the atmosphere in a series of jets at a discharge velocity and from points at a level above the level of said area sufficient to create a substantial induction of the surrounding air into contact with said jets, and effecting ignition of said atomized fuel jets in said series to establish a high temperature flame zone marginally of said area.

18. In a fuel burning fog dispersal system operative in relation to an airfield runway, underground fuel supply conduit means having a portion installed longitudinally of said runway, a series of burner risers individually connected to said conduit means portion, a series of nozzles connected to the upper ends of said risers and arranged to discharge jets of atomized fuel directly into the atmosphere from points adjacent ground level, said risers and the associated nozzles providing a continuation of the fluid supply path provided by said conduit means, a valve in said conduit means between said source and said nozzles, a second underground conduit means connected to said fluid supply path at a point between said valve and the point at which fuel is discharged from said nozzles, and means for subjecting said second conduit means to internal pressure lower than the pressure at which fuel is supplied to said nozzles.

LAMBERT KOOISTRA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STA'IES PATENTS Number Name Date 966,395 Gothan Aug. 2, 1910 1,571,969 Ruprecht Feb. 9, 1926 1,646,503 Stewart Oct. 25, 1927 1,957,207 Harrington May 1, 1934 2,015,923 Davis Oct. 1, 1935 OTHER REFERENCES Aviation News of Dec. 3, 1945, page 12.

The Engineer, issue of June 8, 1945, pages 452 and 453; issue of June l5, 1945, pages 471, 472 and 473; issue of June 22, 1945, pages 486 and 487.

The Engineering Journal (of Canada), issue of October 1945, pages 634, 635, 636, 637, 638, 639 and 640. 

